Relationship between serum cardiac troponin T level and cardiopulmonary function in stable chronic obstructive pulmonary disease

BACKGROUND High-sensitivity cardiac troponin T (hs-cTnT) in serum is a useful marker of acute myocardial injury, yet information is limited in patients with chronic obstructive pulmonary disease. We aimed to explore the association between hs-cTnT levels and cardiac and pulmonary dysfunction in patients with stable chronic obstructive pulmonary disease and at-risk individuals. METHODS We examined community-dwelling adults with/without chronic obstructive pulmonary disease, with a life-long smoking history, current symptoms of dyspnea during exertion, prolonged coughing, and/or sputum. Serum hs-cTnT concentrations were measured, and subjects underwent pulmonary function tests, high-resolution computed tomography of the chest, an echocardiogram, and a 6-minute walking test. RESULTS Eighty-six stable patients were identified (mean age 65.5 years; predicted forced expiratory volume in 1 second [FEV1% predicted] 75.0%). Their overall mean hs-cTnT level was 0.008 ng/mL. Logarithmically transformed hs-cTnT levels significantly and positively correlated with age, smoking index, serum high-sensitivity C-reactive protein levels, right ventricle systolic pressure, low attenuation area percentage, and brain natriuretic peptide levels (range r=0.231-0.534, P=0.000 to P=0.042). Further, logarithmically transformed hs-cTnT values significantly and negatively correlated with forced vital capacity, FEV1% predicted, diffusion capacity, arterial oxygen tension, and 6-minute walking distance (range r= -0.482 to -0.377, P=0.000 to P=0.002). Multivariate analyses showed that hs-cTnT values varied independently according to the following three parameters: high-sensitivity C-reactive protein levels (B=0.157, β=0.450, t=3.571, P=0.001), age (B=0.008, β=0.352, t=2.789, P=0.009), and right ventricular systolic pressure (B=0.008, β=0.280, t=2.202, P=0.035). CONCLUSION Even in patients with stable chronic obstructive pulmonary disease, the serum troponin T concentration was controlled by at least three major factors, ie, systemic inflammation, advancing age, and right cardiac overload.